The present invention relates to non-destructive testing of vehicular tires, and specifically to apparatus and methods for positioning and testing vehicular tires prior to retreading.
It is common to retread worn vehicular tires so that the tires may be reused. Typically, a tire carcass is inspected prior to applying a new tread portion in order to detect any flaws in the carcass, such as a defect in the inner liner, that would make the carcass unsuitable for retreading until repairs can be made.
Visual inspection of a tire carcass to detect flaws has been known for many years, and is typically employed as one part of the inspection before retreading. Visual inspection, however, while useful for detecting gross flaws in tire carcasses being evaluated for possible retreading, is not suited for reliably detecting certain flaws. In particular, flaws that involve a defect too fine or too obscure to detect visually may be inadvertently overlooked and retreaded to produce a defective retreaded tire.
Various testing devices and methods have been developed to supplement visual inspection methods during the tire retreading process. Some prior methods, such as disclosed in U.S. Pat. Nos. 4,297,876 and 4,327,579 each of which is fully incorporated herein by reference, involve the use of ultrasonic energy. Other methods, such as described in U.S. Pat. Nos. 6,304,090 and 4,520,307, which are owned by the owner of the present invention and which are also incorporated fully herein by reference, involve the use of high potential electrical energy. In each of the described methods, detector portions are applied inside and outside of the tire and the tire is rotated to detect flaws.
Tires are generally moved between retread processing steps with automated conveying apparatus to save time and labor in the retreading process. In one type of conveyor in widespread use in retread shops, a series of hooks are suspended from an overhead track. Each hook has a horizontal portion for engaging and supporting the beads of a tire. The tires are moved between processing stations by sliding the hooks along the track.
In prior systems, when a tire is to be tested, it must be physically removed from the conveyor and placed in a bead spreader and/or a tire rotating machine for testing. After testing, the tire must then be physically replaced on the conveyor for further processing. Considerable time and effort is expended in the steps of physically moving tires to and from the conveyor, adding inefficiency and cost to the tire retreading process. In addition, if the tire has been buffed, the buffed surface of the tire is subjected to possible contamination.
What is needed in the industry is an apparatus and method of testing tires wherein the steps of physically moving tires to and from a conveyor for testing are eliminated.
The present invention substantially meets the needs of the industry by providing an apparatus for rotating a tire for testing wherein the tire need not be physically removed from the conveyor. In the invention, a roller coupled with a drive device is supported adjacent the conveyor by a support structure. The roller is selectively positionable in a testing position, wherein the roller engages the beads of the tire and the tire is supported on the roller. The tread area of the tire is not contacted. In this testing position, the drive is used to selectively rotate the roller, thereby rotating the tire about a rotational axis. The detector head of a testing device disposed in the tire rolls or slides on the inside surface of the tire as it rotates to detect any flaws in the tire.
The roller is also selectively positionable in a tire clearing position, wherein the roller is selectively positioned away from the tire. In this position, the tire is supported by the conveyor and may be moved by the conveyor between processing stations.
The selectively positionable roller arrangement of the invention eliminates the need for physically repositioning tires from a conveyor to a tire rotating device for testing, thus saving time and effort in the retreading process. In addition, because the invention includes a tire rotating device, the need for a separate tire rotating device is eliminated, thus saving further costs. Also, contact with the buffed surface of the tire is avoided, thereby improving the quality and reliability of the retreaded tire.
In the invention, an apparatus for selectively positioning a vehicular tire for testing includes a support structure and a tire rotating assembly operably coupled to the support structure. The tire rotating assembly includes a drive portion and at least one roller portion. The roller portion presents a longitudinal axis and is operably coupled to the drive portion so that the roller portion is selectively rotatable about the longitudinal axis with the drive portion. The roller is adapted to be selectively engagable with the bead portions of the tire so that the tire is supported thereon and so that the tire is rotated about the rotational axis when the roller is rotated about the longitudinal axis with the drive portion.
The tire rotating assembly may include a plurality of roller portions, each presenting a longitudinal axis. At least one of the plurality of roller portions is operably coupled to said drive portion in such an arrangement so that the roller portion is selectively rotatable about the longitudinal axis with the drive portion. The roller may be selectively positionable in at least a tire clearing position wherein the roller is clear of the tire, and a testing position, wherein the roller is positioned for receiving and supporting the bead portions of the tire. A linear actuator may be operably coupled to the support structure and the roller to selectively position said the roller in the tire clearing and the testing positions.
The invention also includes a system for inspecting a vehicular tire. The system includes a conveyor, an inspection apparatus positioned adjacent the conveyor, and a testing apparatus positioned proximate the inspection apparatus. The inspection apparatus includes a support structure and a tire rotating assembly operably coupled to the support structure. The tire rotating assembly includes a drive portion and at least one roller portion. The roller portion presents a longitudinal axis and is operably coupled to the drive portion so that the roller portion is selectively rotatable about the longitudinal axis with the drive portion. The roller is selectively positionable in at least a tire clearing position wherein the tire is supported by the conveyor and the tire is movable with the conveyor, and a testing position wherein the roller is engaged with the bead portions of the tire so that the tire is supported thereon and so that the tire is rotated about the rotational axis when the roller is rotated about the longitudinal axis with the drive portion. The testing apparatus has a detector head portion selectively positionable in the tire. The testing apparatus is adapted to detect flaws in the tire as the tire is rotated about the rotational axis with the detector head portion positioned in the tire.
The invention may also include a method of inspecting a vehicular tire. The method includes steps of:
(a) coupling a roller with a drive portion so that the roller is selectively rotatable about the longitudinal axis of the roller with the drive portion;
(b) coupling the roller and drive portion to a support structure;
(c) positioning the tire so that the beads of the tire are engaged with the roller and the tire is supported thereon;
(d) rotating the roller with the drive portion, thereby rotating the tire about the rotational axis; and
(e) inspecting the tire as the tire is rotated about the rotational axis.